The short version of melanocortin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-27. Anything still debated is marked as such rather than presented as settled.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
Regulatory treatment of this peptide varies by country. It holds no marketing authorization as a medicine in the United States, the European Union, or most other jurisdictions. Some countries classify products containing it as prescription-only or unlicensed medicines, which restricts lawful supply. Authorities have issued public notices warning that unregulated products may contain undeclared or incorrect ingredients. The molecule also appears on prohibited lists for competitive sport. These measures address supply oversight rather than any approved therapeutic role.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms add to total mass |
| Molecular mass | About 1024 daltons | Calculated for the free base |
| Structural class | Cyclic heptapeptide | Contains D-phenylalanine and norleucine |
| Parent hormone | Alpha-melanocyte-stimulating hormone | Endogenous tridecapeptide of 13 residues |
| Receptor profile | Non-selective melanocortin agonist | Interacts with MC1R, MC3R, MC4R and MC5R |
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
The peer-reviewed record is dominated by small early-phase studies, case reports and pharmacovigilance summaries rather than large randomised trials. Papers typically examine tanning response, receptor selectivity or patterns of reported adverse events. Many note that participants obtained the peptide outside a clinical setting, which limits verification of composition and administered amount. Reported events vary widely, and causality is frequently unclear because the identity and purity of self-sourced material are unknown. Open questions include whether repeated melanocortin receptor stimulation produces cumulative effects, and how often label claims match actual content.
Melanotan II is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, corresponding to a molecular formula of C50H69N15O9 and a monoisotopic mass near 1024 daltons. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, a peptide hormone produced by cleavage of proopiomelanocortin. A lactam bridge between the aspartate and lysine side chains closes the ring, and the C-terminal amide removes a free carboxyl group. Both modifications increase resistance to enzymatic degradation compared with the linear parent hormone. Four substitutions distinguish it from afamelanotide, the linear analogue studied under the name melanotan I.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
Aerated chocolate is chocolate that has undergone foaming. It has a lower density than other types of chocolate, and a smoother mouthfeel as it melts. Aerated chocolate was first brought to market in 1935 by the British chocolate maker Rowntree's under the brand Aero. Although Rowntree patented the manufacturing process, other chocolate makers quickly began making their own products, and today several manufacturers make aerated chocolates. Aerated chocolate can be divided into four types. The most common, seen in Aero, has large bubbles and is produced under a vacuum, or by beating gas into liquid chocolate under pressure. Aerated chocolate with tiny bubbles uses the same beating gas method but with nitrogen. Aerated chocolates containing long tubes of air are extruded rather than moulded. The final type is an aerated chocolate with low fat content, held together by a skeleton of solid particles. They are made by first dissolving sugar, then forming an emulsion with other ingredients. It finally undergoes evaporation and drying or freeze drying to reduce the water content.
The mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) also interacts with PKCε; phosphorylation of mitoK(ATP) following preconditioning stimuli potentiates channel opening. PKCε modulates the interaction between subunit Kir6.1 of mitoK(ATP) and connexin-43, whose interaction confers cardioprotection. Lastly, several mitochondrial metabolic targets of PKCε phosphorylation involved in cardioprotection following activation with εRACK have been identified, including mitochondrial respiratory complexes I, II and III, as well as proteins involved in glycolysis, lipid oxidation, ketone body metabolism and heat shock proteins. The role of PKCε acting in non-mitochondrial regions of cardiomyocytes is less well understood, though some studies have identified sarcomeric targets. PKCε translocation to sarcomeres and phosphorylation of cTnI and cMyBPC is involved in the κ-opioid- and α-adrenergic-dependent preconditioning that slows myosin cycling rate, thus protecting the contractile apparatus from damage. Activation of PKCε by εRACK prior to ischemia was also found to phosphorylate Ventricular myosin light chain-2, however the functional significance remains elusive. Actin-capping protein, CapZ appears to affect the localization of PKCε to Z-lines and modulates the cardiomyocyte response to ischemic injury. Cardioprotection in mice with reduction of CapZ showed enhancement in PKCε translocation to sarcomeres, thus suggesting that CapZ may compete with PKCε for the binding of RACK2.
telomeric silencing The repression of transcription of genes in regions adjacent to telomeres. Telomeres also appear to reduce the accessibility of subtelomeric chromatin to modification by DNA methyltransferases.
Sources: en.wikipedia.org
The prostate is an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemically, and physiologically. Anatomically, the prostate is found below the bladder, with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular and connective tissue. The prostate produces and contains fluid that forms part of semen, the substance emitted during ejaculation as part of the male sexual response. This prostatic fluid is slightly alkaline, and milky or white in appearance. The alkalinity of semen helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm. The prostatic fluid is expelled in the first part of ejaculate, together with most of the sperm, because of the action of smooth muscle tissue within the prostate. In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid, those in prostatic fluid have better motility, longer survival, and better protection of genetic material. Disorders of the prostate include enlargement, inflammation, infection, and cancer. The word prostate is derived from Ancient Greek prostátēs (προστάτης), meaning "one who stands before", "protector", "guardian", with the term originally used to describe the seminal vesicles.
Pre-mature (early) cultivars are harvested before the end of July, serotinous (late) cultivars from September on, and mid-serotinous or mid-matutinal cultivars are in between these harvest times. Using pre-mature cultivars, rhizomes can be harvested earlier and sold for a higher price. Adlittoral (shallow), deep, and intermediate cultivars are distinguished according to the depth in which the rhizomes grow underground. Adlittoral cultivars range from 10 to 20 cm (3.9 to 7.9 in) depth and are often premature. They develop faster due to higher temperatures in surface soil layers. When harvested in July, adlittorals have higher yields than deeper-growing cultivars, but not necessarily when harvested in September. Rhizomes of adlittoral cultivars are crisp and good for frying purposes. Deep cultivars grow more than 40 cm (16 in) deep. They are often serotinous and can harvest high yields. Their rhizomes are starch-rich. The main popular Nelumbo nucifera cultivars in China are Elian 1, Elian 4, Elian 5, 9217, Xin 1, and 00–01. The average yield of these cultivars is 7.5–15 t/ha (3.3–6.7 tons/acre) of harvest in July and 30–45 t/ha (13–20 tons/acre) of harvest in September. In Australia, the cultivar grown for the fresh rhizome market in Guangdong and Japan, the common rhizome cultivars are Tenno and Bitchu.
In China, penis is eaten in traditional Chinese medicine to treat erectile dysfunction. Penis is euphemistically known as bian ('whip'). Chongqing penis stew is a delicacy of Chongqing, featuring Sichuan pepper.
Sources: en.wikipedia.org
Refers to trials that are conducted to find better tests or procedures for diagnosing a particular disease or condition. Diagnostic trials usually include people who have signs or symptoms of the disease or condition being studied. (NLM) Direct Access
=== 2000–2002: The beginning of the rivalry === 50 Cent's single "How to Rob" quickly became an underground hit throughout New York and 50 Cent soon began work on his major label debut Power of the Dollar, set for release in 2000. Despite 50 Cent's local success with "How To Rob", his local success paled in comparison to Ja Rule's following the release of Rule 3:36 later that same year. Tensions began to form beyond conflicts between the two crews and record labels. In February 2000, both 50 Cent and Ja Rule were scheduled to perform at the same Atlanta nightclub. Prior to the performances, music executive Chaz “Slim” Williams who was managing 50 Cent at the time, arranged a meeting between 50 Cent and Ja Rule to discuss ending their dispute. According to multiple accounts, the meeting escalated into a physical altercation after Ja Rule, who was holding a baseball bat, allegedly made threatening gestures toward 50 Cent. In response, 50 Cent reportedly attempted to strike Ja Rule, prompting a scuffle between the two. Accounts of the incident differ regarding what occurred next. 50 Cent has claimed to have punched Ja Rule, knocked him unconscious and took his chain while Ja Rule has maintained that he struck 50 Cent with the baseball bat before the two engaged in a physical struggle. Black Child, an associate of Ja Rule, later alleged that members of Ja Rule’s entourage chased 50 Cent through a nearby hotel following the incident.
== Research == Gene therapy is currently being studied as a possible treatment for chronic granulomatous disease. CGD is well-suited for gene therapy since it is caused by a mutation in single gene which only affects one body system (the hematopoietic system). Viruses have been used to deliver a normal gp91 gene to rats with a mutation in this gene, and subsequently the phagocytes in these rats were able to produce oxygen radicals. In 2006, two human patients with X-linked chronic granulomatous disease underwent gene therapy and blood cell precursor stem cell transplantation to their bone marrow. Both patients recovered from their CGD, clearing pre-existing infections and demonstrating increased oxidase activity in their neutrophils. However, long-term complications and efficacy of this therapy were unknown. In 2012, a 16-year-old boy with CGD was treated at the Great Ormond Street Hospital, London with an experimental gene therapy that temporarily reversed the CGD and allowed him to overcome a life-threatening lung disease. In 2024, Prime Medicine began a Phase 1/2 open-label clinical trial to evaluate PM359, an investigational gene therapy, in patients with CGD caused by NCF1 mutations. The treatment involves transplantation of autologous CD34+ stem cells modified by prime editing ex vivo. Following an announcement of preliminary results in May 2025, Prime Medicine and its clinical collaborators reported in December 2025 that two CGD patients treated with PM359 had been "effectively cured" of the disease.
Sources: en.wikipedia.org
No regulatory agency has authorised melanotan-2 as a medicine for any indication. It circulates mainly as a research chemical or through unregulated channels. As a result, identity, purity and content are not independently guaranteed.
Melanotan-1, also called afamelanotide, is a linear analogue with greater selectivity for MC1R and has received approval in some jurisdictions for a specific photosensitivity disorder. Melanotan-2 is cyclic, less selective, and reaches central receptors more readily. The two are often confused in online discussion despite different pharmacology and regulatory status.
Alpha-MSH is an endogenous tridecapeptide derived from pro-opiomelanocortin. Melanotan-2 reproduces its core receptor-binding sequence inside a shortened, stabilised ring. The result is a molecule with a longer effective half-life and higher potency than the parent hormone.
Only a small number of early-stage human studies have been reported, and most were limited in size and duration. No large late-stage program has established a general efficacy or safety profile. The evidence base is therefore thin compared with approved medicines.